Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle. One particular component of bicycles which have been extensively redesigned over the past years is the bicycle brake device. Bicycle brake devices are constantly being redesigned to be lighter and to provide additional braking power.
There are several types of bicycle brake devices which are currently available on the market. Examples of some types of common bicycle brake devices include rim brakes and caliper brakes. With respect to caliper brakes, there are mainly three types of caliper brakes: a side pull type, a center pull type and a cantilever type. In a side pull type of caliper brake device, a pair of brake arms are pivotally connected together about a center mounting bolt which attaches to the frame of the bicycle. Each of the brake arms has a lever portion which is coupled to the brake wire such that when the rider operates the brake lever of the brake operating device, the lever portions of the brake arms are pulled together, which in turn moves the brake shoes attached to the other end of the brake arms together against the rim of the bicycle wheel. A return spring is provided for biasing the brake arms away from the bicycle wheel rim when the rider releases the brake lever. Side pull types of caliper brake devices are commonly used in road bikes.
A center pull type of caliper brake device operates similar to the side pull type, except that the brake arms are attached to a brake arm bridge such that each brake arm is pivotally coupled at a separate pivot point on the brake arm bridge. The brake arm bridge is attached directly to the frame of the bicycle. A straddle cable interconnects the two lever portions of the brake arms such that a main brake wire is coupled to the straddle wire for pulling the lever portions of the brake arms together.
A cantilever type of brake device is generally mounted on bicycles which are designed for off-road use such as mountain bikes (MTB) and all terrain bikes (ATB). In particular, a cantilever type brake device is designed to provide a more powerful braking force. A cantilever type brake device is equipped with a pair of brake arms which are rotatably supported in a cantilever fashion on the front or rear fork of the bicycle frame, with the brake shoes attached to an upper portion of the brake arms. Typically, the lower end of the brake arms are rotatably supported on the brake frame and the upper end is linked to a brake cable or wire. The brake shoes are arranged opposite one another on either side of the bicycle wheel rim which is located between the arms. With this cantilever type of brake device, the bicycle arms rotate in the closing direction when the brake cable is pulled by the brake lever, which in turn results in the brake shoes being pressed against the rim of the bicycle wheel to apply a braking force.
Cantilever types of brake devices have several advantages over side pull types of caliper brake devices. For example, with such a cantilever brake device, there is no need to vary the shape of the brake device with the size of the bicycle as may be the case with a side pull type caliper brake device. Moreover, cantilever type of brake devices apply a more equal braking force than a side pull type caliper brake.
To further increase the braking force applied to the wheel rim, U-shaped boosters have been designed for attaching to cantilever type of brake devices for increasing the structural rigidity of brake devices. In particular, the booster is typically a U-shaped member having its lower free ends attached to the pivot points of each of the brake arms. Accordingly, the booster reduces the amount of outward deflection of the brake arms when a braking force is applied by the brake shoes against the bicycle wheel rim. There are currently several different types of boosters that are available on the market. Typically, the U-shaped booster is constructed out of a lightweight metallic material such as aluminum. More recently, boosters have been constructed from carbon fiber composite materials. However, the boosters constructed of carbon fiber composite materials are typically expensive to manufacture and therefore has not gained a lot of popularity.
In view of the above, there exists a need for a booster which increases the stiffness of a brake device and which is lightweight. This invention addresses this need in the art as well as other needs in the art which will become apparent to those skilled in the art from this disclosure.